Corresponding author: Volker Dietze ( dietze.v@t-online.de ) Academic editor: Alexander Nützel
© 2021 Norbert Wannenmacher, Volker Dietze, Matthias Franz, Günter Schweigert.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Wannenmacher N, Dietze V, Franz M, Schweigert G (2021) New records of ostracods and ammonites from the Aalenian (mainly Concavum Zone) of the Zollernalb (Swabian Alb, SW Germany). Zitteliana 95: 1-55. https://doi.org/10.3897/zitteliana.95.56296
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The lithostratigraphy and ammonite/ostracod biostratigraphy and the accompanying fauna of several sections and outcrops around the Hohenzollern (Zollernalb, SW Germany), ranging from the topmost Opalinuston Formation (uppermost Lower Aalenian) to the basal Wedelsandstein Formation (lowermost Lower Bajocian) are described and analyzed. The study of ostracods from 41 samples from the Aalenian and Lower Bajocian of the Heiligenbach, Hausterberg and Roschbach sections has yielded approximately 4,100 specimens. Significant changes in the ostracod assemblage occur at the base of the Lower Aalenian “Comptum” Subzone, at the Bradfordensis/Gigantea subzonal boundary, at the Bradfordensis/Concavum zonal boundary and at the Aalenian/Bajocian boundary (Concavum/Discites zones). A minor change occurs above the Calceola-Bank within the Concavum Zone. The following new ostracod species are described: Cytheropterina crassicostata sp. nov., Eucytherura eberti sp. nov. and Eucytherura foveolata sp. nov. In addition, 15 presumably new species are briefly described; 10 ‘incertae sedis’ taxa are figured, but left in open nomenclature. The ammonite faunas of the Inopernabank and Konglomeratbank beds (Upper Aalenian, Bradfordensis Zone, Gigantea Subzone) as well as the ammonite faunas from the Calceolabank and Rostrote Kalkbank beds (Upper Aalenian, Concavum Zone, Concavum Subzone, cavatum biohorizon) are described and correlated with those of other areas.
Die Lithostratigraphie und die Ammoniten-/Ostracoden-Biostratigraphie sowie die Begleitfauna mehrerer Profile und Aufschlüsse in der Umgebung des Hohenzollern (Zollernalb, SW-Deutschland), von der obersten Opalinuston-Formation (oberstes Unter-Aalenium) bis zum basalen Wedelsandstein (unterstes Unter-Bajocium), werden beschrieben. Die Auswertung von 41 Proben (aus dem Aalenium bis zum Unter-Bajocium) vom Heiligenbach, Hausterberg und Roschbach hat ca. 4100 Ostracoden erbracht. Signifikante Änderungen in der Ostracoden-Gemeinschaft gibt es an der Basis der “Comptum”-Subzone (Unter-Aalenium), den Grenzen der Bradfordensis-/Gigantea-Subzone, der Bradfordensis-/Concavum-Zone sowie an der Aalenium/Bajocium Grenze (Concavum-/Discites-Zone). Eine weniger stark ausgeprägte Änderung der Ostracoden-Gemeinschaft erfolgt innerhalb der Concavum-Zone, oberhalb der Calceola-Bank. Folgende neue Arten werden beschrieben: Cytheropterina crassicostata sp. nov., Eucytherura eberti sp. nov. und Eucytherura foveolata sp. nov. Darüber hinaus werden 15 wahrscheinlich neue Arten kurz beschrieben; 10 “incertae sedis”-Taxa werden in offener Nomenklatur abgebildet. Die Ammonitenfaunen der Inopernabank und der Konglomeratbank (Ober-Aalenium, Bradfordensis-Zone, Gigantea Subzone) werden ebenso wie diejenige der Calceolabank und der Rostroten Kalkbank (Ober-Aalenium, Concavum-Zone, Concavum-Subzone, cavatum-Horizont) beschrieben und mit Ammonitenfaunen anderer Gebiete korreliert.
Upper Aalenian, Achdorf Formation, ammonites, ostracods, Zollernalb, SW Germany
Ober-Aalenium, Achdorf-Formation, Ammoniten, Ostracoden, Zollernalb, SW-Deutschland
In the context of the field works on the occasion of the investigation of the lithostratigraphy as well as the ammonite and ostracod biostratigraphy of the “Unterer Wedelsandstein” and “Sowerbyi-Oolith” members (Wedelsandstein Formation; Lower Bajocian) of the Zollernalb (
Our knowledge on the Aalenian ostracod fauna from Germany is mainly based on studies from the 1930’s to 1960’s as summarized by
There is only little information available on the ammonites of the uppermost Aalenian (Concavum Zone) in SW Germany. Stratigraphic data and numerous local details were provided by
All sections are described bottom-up.
Opalinuston Formation (Zillhausen Member)
Bed no.
Achdorf Formation
Wedelsandstein Formation
34–36. [Sowerbyi-Oolith (= beds 11–13 in
Higher up Unterer Wedelsandstein (see
Landslide above the former Friedrichstal castle near Hechingen-Boll
Achdorf Formation
Bed no. / sample no.
2.3.1 Mühlbächle
Achdorf-Formation:
Bed no. / sample no.
Wedelsandstein-Formation:
Higher up follows the Unterer Wedelsandstein (see
2.3.2 Starzel (river bed near the road Jungingen–Killer, see
Achdorf-Formation:
bed no.
2.4.1 Heiligenbach
(the strata below bed 1 were not studied in detail)
Bed no. / sample no.
“Ob -1m“ He19-1 1.0 m below Onkoidbank.
“Ob“ (0.15–0.2 m) [Onkoidbank]: L. opalinum [m], about 11 m below “Wasserfallschichten”. In its upper part a marly limestone, dark grey, upper and lower surface very irregular, with shrinkage cracks and oncoids (Fig.
“x” (about 11 m): sandy, carbonaceous claystone, a single Lytoceras dilucidum.
“WS” (about 14–15 m) [Wasserfallschichten]: with several cascades in the river bed (
In the upper 0.25 m single mica-bearing fine sandy limestone plates (up to approx. 0.03 m thick) with a rich ichnofauna, Gyrochorte comosa.
This outcrop is covered by terrace gravel of the Heiligenbach.
2.4.2 Eastern tributary of the Heiligenbach coming from the Sießenwald, approx. 30 m east of the “Hunnengrab”
In the river bed there is a light grey, hard limestone bed (0.15 m) with a rust-coloured rim and many burrows. Its lithology resembles the lower bed of the Rostrote Kalkbank from the Mühlbächle section at Jungingen. An indeterminable ammonite fragment. A larger Euaptetoceras sp. (SMNS 70519/5) comes from a loose block of the Rostrote Kalkbank.
2.4.3 Hanneswiesle
This outcrop is located on a forest path in the Hanneswiesle district west of Beuren.
Bed no.
Obere Onkoidbank, polished section; the lower half of dark grey limestone bed consists of redeposited, marginally eroded, micritic oncoids up to 7 × 8 cm in size. This part is overlain by silty, fine sandy, fossil-bearing (crinoids, bivalve shells, rare belemnites) marly limestone, in which up to 4 cm large oncoids with borings and thin pyritized microbial crusts are embedded. This sediment also fills the interspaces between the oncoids. Opalinuston Formation, Heiligenbach. Width of the photo: 20 cm.
Section Heiligenbach, upper part, above the Rostrote Kalkbank, combined with the Mühlbächle, Roschbach and Hausterberg sections. WS = Wedelsandstein Formation; Murchis. = Murchisonae; Di. = Discites Zone; Op. Sz. = Opalinum Subzone; “Co. Sz. = “Comptum” Subzone; Bradf. Sz. = Bradfordensis Subzone.
Since we did not find Aalenian ammonites in this outcrop, we here refer to
For the present study, a total of 41 samples were taken in September 2018 and September 2019. Individual samples, which were already taken in 1988 at the Heiligenbach, were included in the investigation.
Microfossils have been extracted by first drying the samples (0.5–1 kg), breaking them down with the aid of hydrogen peroxide (3% solution of H2O2) and then sieving them under water. The residues were then cleaned by boiling them for 15 minutes in a moderately concentrated sodium chloride solution (3 teaspoons NaCl / 0.25 l water). From the fractions > 0.5 mm and > 0.315 mm of the residues, 3–5 trays were examined. From the fractions > 0.2 mm and > 0.15 mm we examined 3 trays.
Photographs were taken using SEM in Stuttgart (SMNS).
The investigation of the Geisingen clay pit (
The 41 samples yielded a total of 4,149 specimens, ranging from 0 to > 700 specimens per sample. For a semi-quantitative analysis of the composition of the ostracod assemblages the greater numbers of single (right or left) valves were counted as 1, resulting in a total of 2.758 individuals.
A total of 108 species were identified, 329 specimens remained undetermined. From 34 species of the Upper Opalinuston Formation, 22 do not cross the boundary to the overlying Achdorf Formation. The Achdorf Formation yielded a total of 82 species including the 12 already known from the Opalinuston Formation. In the Lower Wedelsandstein Formation 4 new species appear, 11 persist from the Aalenian.
At zone or subzone level, two relative maxima in the total number of species are recorded in the Opalinum Subzone and Concavum Zone (Table
Short descriptions of new species of cytherurids (Eucytherura sp. 3–11, Procytherura sp. 2, P. sp. 5, Procytheropteron sp. 1) in our material are excluded. Ten presumably new species were found only in numbers of one to five specimens and could not be assigned to any known genus. For this reason, these taxa were left in open nomenclature. In the samples of the fine sandy layers, the ostracods are partly covered by remnants of sediment (mainly quartz grains) and/or fragmentarily preserved.
LGRB Landesamt für Geologie, Rohstoffe und Bergbau im Regierungspräsidium Freiburg, Germany;
SMNS Staatliches Museum für Naturkunde Stuttgart, Germany;
C carapace;
RV right valve;
LV left valve;
HT Holotype.
In the following, the ostracod taxa that were found in the studied sections are listed in systematic order with information on their known occurrence. For detailed lists of synonyms, reference is made to
Family Polycopidae Sars, 1866
Genus Polycope Sars, 1866
2 V in sample He19-9 and Mü I.
Upper Toarcian to Upper Bathonian.
2 C in sample He19-27
Upper Aalenian, Concavum Zone; SW Germany.
1 C, 4 V in samples He19-15–21.
Upper Aalenian, Murchisonae Zone – Concavum Zone; SW Germany.
Remarks: The material comprises predominantly very small, smooth carapaces and valves with no visible ornamentation and therefore it is not determinable to species level under the microscope. It cannot be excluded that they belong to different species.
Family Cytherellidae Sars, 1866
Genus Cytherella Jones, 1849
30 C, 585 RV, 517 LV in samples He19-14–28, Mue19-1, Ha19-2–5 and Ro19-1–2.
Upper Toarcian to Lower Oxfordian; SW Germany, Ireland.
12 RV in samples He19-24 and Ro19-1–2.
Upper Aalenian, Concavum Zone; SW Germany.
This ?subspecies was first described and figured from Thanheim (
1 C, 2 RV, 4 LV in samples He19-26 and Ro19-1–5.
Upper Aalenian, Concavum Zone; SW Germany.
11 C, 18 RV, 28 LV in samples Ha19-4–6 and Ro19-1.
Upper Aalenian to Lower Bajocian; England, France, SW Germany.
2 RV, 1 LV in samples He19-17–18.
Upper Aalenian to Bathonian; England, France, SW Germany.
1 C, 1 RV, in samples He19-18–19.
Toarcian to Lower Bajocian; SW Germany, Great Britain.
Genus Liasina Gramann, 1963
2 RV, 1 LV in samples Ha19-2–4 and Lin18-1.
Toarcian to Aalenian; SW Germany, Ireland.
Genus Cardobairdia van den Bold, 1960
4 RV and 2 LV in samples He19-3–8.
Lower Aalenian, Opalinum Zone; SW Germany, N Switzerland.
1 LV in sample He19-26.
Toarcian to Aalenian; SW Germany, Ireland.
Genus Bairdiacypris Bradfield, 1935
1 C, 1 RV in samples He19-19 and He19-22.
Toarcian to Aalenian; SW Germany, Ireland.
Genus Paracypris Sars, 1866
1 RV, 2 LV in sample He19-12.
Lower Aalenian, Opalinum Zone; SW Germany.
1 C in sample He19-1.
Lower Aalenian, Opalinum Zone; SW Germany.
The specimen is very small and preserved in pyrite and could therefore not be assigned with certainty to any species.
Genus Macrocypris Brady, 1868
4 C samples in He19-19–21.
Lower Aalenian to Lower Oxfordian; Germany, Scotland, N Switzerland, Russia.
4 C, 3 RV, 1 LV in sample He19-27 and Ro19-3.
Toarcian to Upper Aalenian; England, SW Germany; Upper Bathonian; N Germany.
1 C, 1 R in samples He19-1 and He19-7.
Lower Aalenian, Opalinum Zone; SW Germany.
Genus Bythoceratina Hornibrook, 1952
1 C, 8 RV, 9 LV in samples He19-16–27 and Ro19-4–5.
Upper Aalenian, Murchisonae to Concavum zones; SW Germany.
A species of Praebythoceratina which is distinguished by the combination of the following features: an U-shaped lobe with an irregularly reticulate spine in the ventro-central area. Its anterior branch is strongly convex and irregularly reticulate, with dominant subvertical ridges. The posterior branch is broad and gently arched and covered with irregular pores. Along the anterior margin there is a pronounced bulge, which is also irregularly reticulate.
2 C, 6 RV, 7 LV in samples He19-21–27 and Ro19-1–3.
Upper Aalenian, Concavum Zone; SW Germany.
1 LV in sample He19-9.
Lower Aalenian, Opalinum Zone; SW Germany.
3 RV, 1 LV in sample Mue19-1.
Upper Aalenian, Concavum Zone; Germany.
This genus is in need of a revision and currently of unclear composition (
2 C in sample He19-21 and Ro19-1.
Upper Aalenian, Concavum Zone; SW Germany.
1 C in sample He19-27.
Upper Toarcian to Upper Aalenian; SW Germany, Portugal.
Genus Cytheropterina Mandelstam, 1956
4 RV, 14 LV in samples He19-27, Mue19-1, Ha19-2 and Ro19-4–5.
Upper Aalenian, Bradfordensis Zone (Gigantea Subzone) to Concavum Zone; SW Germany.
53 RV, 50 LV in samples He19-16–27, Mue19-1, Ro19-1–5, Ha19-2.
Lower Aalenian to Lower Bajocian; SW Germany.
crassus (lat.) = coarse, fat; costatus (lat.) = ribbed; referring to the broad rounded ribs.
Right valve, figured on Fig.
two left valves, one right valve, figured on Fig.
Heiligenbach valley near Hechingen-Beuren (SW Germany).
Achdorf Formation, claystone above the Calceolabank, bed no. 46 in Fig.
11 RV, 11 LV in samples He19-26–27, Mue19-1 and Ro19-4–5.
Medium size. Subtriangular outline, with broad, rounded irregular ribs; the underside of the alate extension being smooth except for its posterior part.
Carapace medium-sized, subtriangular. Right and left valve (identical in outline and ornamentation): Anterior margin symmetrically rounded. The dorsal margin is straight, medianly slightly concave. The ventral margin converges, partly straight or in a slight curve, to the acuminate posterior end. The ventral margin is obscured by a broad triangular wing. The anterior and posterior marginal zones are covered with roundish pits. The anterior marginal zone is offset with a small, asymmetrically rounded step against the lateral surface. A broadly rounded, mediodorsally-anteroventrally running rib forms a second step running diagonally over the anterior half of the valve. From this rib another broad rib branches off slightly below the middle, running subvertically towards the edge of the wing. The adjoining surface, which ends in the symmetrically rounded tip of the broad wing, is characterised by three wide, flat, bulbous elevations separated by wide furrows and pits. The furrows and pits as well as the ribs and depressions are covered with roundish secondary pits. Posteriorly, this area is bounded by a slightly curved, subvertical, rounded rib that tapers from dorsal to ventral. The posterior marginal zone is offset with a further, almost straight, subvertical step. Marginal zone wide anteriorly (Fig.
Cytheropterina crassicostata resembles in outline Cytheropterina bicuneata (Braun) as reported by
Upper Aalenian, Bradfordensis Zone (Gigantea Subzone) to Concavum Zone; SW Germany.
1 C, 4 LV in samples He19-7–12.
Lower Toarcian to Upper Bajocian; France, Germany, Ireland, Spain, N Switzerland.
2 RV in samples He19-12 and from the Geisingen clay pit.
Upper Toarcian to Lower Bajocian; Germany, Ireland.
2 RV, 1 ? LV in samples He19-1 and He19-12.
Upper Toarcian to Lower Bajocian; Germany, Ireland.
3 C, 4 RV, 6 LV in samples He19-5–26.
Upper Toarcian to Lower Bajocian; SW Germany, Ireland.
1 C in sample He19-15.
Lower Aalenian to Lower Bajocian; SW Germany; mid-Callovian; Argentina.
1 RV in sample He19-8, 1 C in the Geisingen clay pit.
Lower Aalenian, Opalinum Zone; SW Germany.
Very small, subovoidal outline in lateral view. Lateral surface with five broadly rounded ribs, subhorizontal in the midventral to posteromedian area; in the anterior half of the valve bent anteroventrally. Roughly reticulated in the region of these ribs by subvertical transverse ribs.
1C, 1 RV in samples He19-24–25.
Upper Aalenian, Concavum Zone; SW Germany.
Very small, subtriangular outline in lateral view. Lateral surface weakly ornamented by two fine longitudinal ribs delimiting a spindle-shaped field, posteriorly rounded and anteriorly pointed. Parallel to the anterior margin there is a third, also very fine rib. Another middorsal-midanterior rib halves the acute-angled triangular field between the frontal rib and the upper longitudinal rib.
1 LV in sample He19-8.
Lower Aalenian, Opalinum Zone; SW Germany.
Eucytherura aff. scottia(Whatley, 1970). – 2018 Franz et al., p. 72, plate 3: 17.
Eucytherura aff. scottia(Whatley). – 2019 Dietze et al., fig. 11.
In honour of the German palaeontologist Martin Ebert, who initiated the investigation of the Geisingen clay pit with his extensive preliminary work.
carapace, figured on Fig.
two carapaces, figured on Fig.
Heiligenbach valley near Hechingen-Beuren (SW Germany).
Achdorf Formation, claystone below the Inopernabank, bed no. 39 in Fig.
10 C, 28 RV, 34 LV from the Heiligenbach, Thanheim and Roschbach sections and the Geisingen clay pit.
A new species of Eucytherura with broad, smooth posterodorsal, frontal and ventral ribs. Intercostate areas weakly reticulate.
Very small, subrectangular. Left valve slightly larger than right with anterodorsal and posterodorsal overlap. Anterior margin weakly rounded with extremity below mid-height; posterior margin pointed in right and bluntly rounded in left valve, apex above mid-height. Posterior cardinal angle pronounced in both valves; anterior cardinal angle more rounded in right than in left valve. Dorsal margin slightly convex to straight; ventral margin medianly slightly convex. Greatest height at anterior cardinal angle; greatest width antero-ventrally; greatest length above mid-height. Ornament consists of a series of broad longitudinal ribs and swellings, and with weakly reticulate intervening areas. A broad, posteriorly weakly alate rib extends from a postero-ventral position across the ventro-lateral surface of the valve, terminating antero-ventrally. A similar broad rib extends mid-posteriorly to mid-dorsally. The eye tubercule is well developed and is connected to a narrower frontal rib, which parallels the anterodorsal margin. A less prominent second rib or elongate swelling parallels the latter mid-anteriorly. Intercostate areas are weakly reticulate, with a characteristic row of small elongate pits above the muscle-scar field. 3–4 small marginal denticles occur anteriorly. Normal pores few and wide-spaced. Internal details not observed.
Euytherura eberti closely resembles Eucytherura scottia Whatley, 1970 from the Callovian and Oxfordian of Scotland. It differs mainly in the length of the dorsal rib, the absence of the anterior tubercles, being replaced by two parallel ribs and the pits above the musclescar-field.
Lower Aalenian to Upper Aalenian, Opalinum to Bradfordensis zones (Gigantea Subzone); SW Germany.
Eucytherura sp. 4. – 2018 Franz et al., p. 72, plate 3: 22
From fovea (lat.) = pit; referring to the characteristic pits on the lateral surface.
One carapace, figured in Fig.
Two carapaces, figured in Fig.
Drillcore KB 1/93 Geisingen (SW Germany).
Opalinuston Formation, Zillhausen Subformation, sample G08Fr, Lower Aalenian.
19 C, 2 RV, 2 LV from samples He 19-3–12 and from the Geisingen clay pit.
A small-sized species of the genus Eucytherura with the following characteristics: pitted lateral surface with a fine median rib.
Very small, subrectangular. Left valve slightly larger than right with dorsal overlap. Anterior margin rounded with extremity slightly below mid-height; posterior margin pointed in right and bluntly rounded in left valve, apex above mid-height. Posterior cardinal angle rounded; anterior cardinal angle pronounced in both valves. Dorsal margin straight in left, slightly convex in right valve; ventral margin straight or slightly concave. Greatest height at anterior cardinal angle; greatest length above mid-height. Ornament consists of a fine median, horizontal or subdiagonal rib, accompanied on both sides by shallow, about 15 μm wide, round or subangular pits with a rough surface. A third row of such pits running antero-medianly – postero-ventrally; further pits in variable numbers and positions scattered on the lateral surface. Particularly striking are 4 rhomboidally grouped pits (Fig.
All other previously known species of Eucytherura have a well-developed ornamentation with sharp or broad ribs and/or reticulate surfaces.
Lower Aalenian, Opalinum Zone; SW Germany.
2C, 1 RV, 8 LV in samples He19-3–26 and Ro19-2.
Toarcian to Upper Aalenian; England, SW Germany.
2 C, 2 RV, 8 LV in samples He19-3–18 and Ro19-4–5.
Upper Pliensbachian to Lower Bajocian; Denmark, England, Sweden, Germany, Argentina, ? Australia.
5 C, 2 LV in samples He19-19–25, Ha19-4–5.
Upper Aalenian, Bradfordensis Zone (Gigantea Subzone) to Concavum Zone; SW Germany.
1 C, 3 RV, in samples He19-1–7.
Lower Aalenian, Opalinum Zone; SW Germany, N Switzerland.
13 C, 9 RV, 7 LV in samples He19-3–28, Ha19-4–5 and Ro19-3–5.
Pliensbachian to Bajocian; Argentina, Egypt, England, Germany, Ireland, North Africa, Wales.
Tethysia sp. 1 Tesakova. – 2018 Franz et al., p. 71, plate 3: 12.
Eucytherura ? sp. 10. – 2019 Dietze et al., plate 7: 21.
1C, 10 RV, 6 LV in samples He19-19–27, Ro19-1, and from the Thanheim section and the Geisingen clay pit.
Upper Aalenian to Lower Bajocian; Argentina, SW Germany.
1 LV in sample He19-27.
Upper Aalenian to Lower Bajocian; Argentina, SW Germany.
This specimen closely resembles plate 1: 7 in
1 LV in sample He19-25.
Lower Aalenian, Opalinum Zone; SW Germany, N Switzerland.
Eucytherura sp. 1, Euc. sp. 3 and Euc. sp. 5 were first named and figured by
5 RV, 1 LV in samples He19-2–12; 17 C, 1 RV from the Geisingen clay pit; 1 C from the Benken borehole (Switzerland).
Lower Aalenian, Opalinum Zone; SW Germany, N Switzerland.
Very small, subrectangular. Left valve slightly larger than right with dorsal overlap. Anterior margin rounded with extremity slightly below mid-height; posterior margin pointed in right and bluntly rounded in left valve, apex above mid-height. Posterior cardinal angle rounded; anterior cardinal angle pronounced in both valves, slightly more rounded in right valve. Dorsal and ventral margins slightly convex in both valves. Greatest height at anterior cardinal angle; greatest length above mid-height. Shell ornamentation reduced to a regular reticulation with rounded meshes of uniform size. Hemispherical eye-tubercle well developed. Internal details not observed.
25 C, 4 RV, 4 LV in samples He19-6–18 and from the Geisingen clay pit.
Lower to Upper Aalenian, Opalinum to Bradfordensis zones; SW Germany.
Very small, subrectangular. Left valve slightly larger than right with dorsal overlap. Anterior margin rounded with extremity slightly below mid-height; posterior margin pointed in right and bluntly rounded in left valve, apex above mid-height. Posterior cardinal angle rounded; anterior cardinal angle pronounced in both valves, slightly more rounded in right valve. Dorsal margin straight in right valve and slightly convex in left valve. Greatest height at anterior cardinal angle; greatest length above mid-height. Shell surface regularly reticulate with rounded meshes of uniform size. Hemispherical eye-tubercle well developed. Starting from the eye-tubercle, a fine frontal rib, straight in the left valve, convex in the right valve, runs parallel to the anterodorsal margin. A second rib runs subvertically from the eye-tubercle and then bends mid-anteriorly to the anterior margin. A ventral rib starts posteroventrally and ends midventrally with its anterior end slightly ascending towards the ventromedian side. A short subvertical ridge is located at the posterior cardinal angle. Internal details not observed.
1 C in sample He19-19; 5 RV, 1 LV from the Geisingen clay pit.
Lower to Upper Aalenian, Opalinum to Bradfordensis zones; SW Germany.
Very small, subovoidal. Anterior margin asymmetrically rounded with extremity below mid-height; posterior margin pointed, apex above mid-height. Posterior cardinal angle rounded; anterior cardinal angle pronounced in both valves. Dorsal margin slightly convex, ventral margin convex. Greatest height at anterior cardinal angle; greatest length above mid-height. Shell surface irregularly and coarsely reticulated. The most striking feature is the gently undulating surface with slight anterodorsal, middorsal and anteroventral depressions. The eye-tubercle is fused with a short, indistinct frontal rib. A short bulge-like rib is located at the posterior cardinal angle. Internal details not observed.
1 RV, 1 LV in samples He19-24–25.
Upper Aalenian, Bradfordensis Zone (Gigantea Subzone) to Concavum Zone; SW Germany.
Very small, subovoidal. Anterior margin asymmetrically rounded with extremity below mid-height; posterior margin rounded, apex above mid-height. Anterior and posterior cardinal angles rounded; both slightly more pronounced in right valve. Dorsal margin slightly concave in ther right valve, slightly convex in the left one. Greatest height at anterior cardinal angle; greatest length above mid-height. Shell surface reticulate, with wide rectangular to polygonal meshes. Eye-tubercle absent.
Right valve : A long, well-defined frontal rib runs from the anterior cardinal angle to the anteroventral margin. The lateral surface is characterized by three fine ribs, the first of which starts in the median region, runs a short distance towards the anterior cardinal angle, then bends perpendicularly towards the anterior margin and after a second 45° bend towards the anteroventral margin. The median rib starts mid-posteriorly above mid-height and ends anteromedianly below mid-height. A long, upwardly curved ventral rib runs from the posteroventral margin to the anteroventral region. One (or two) ribs parallel the ventral rib on the ventral side of the valve.
Left valve : The frontal rib is slightly curved (preservation?) and only weakly developed. The (dorso)median – mid-anterior rib meets the ventral rib at an 60° angle. The median rib starts mid-posteriorly above mid-height and ends anteromedianly at mid-height. Two ribs parallel the ventral rib on the ventral side of the valve. Further, especially internal details were not observed, partly for preservation reasons.
1 RV, 2 LV in samples He19-18 and He19-24–25.
Upper Aalenian, Bradfordensis Zone; SW Germany.
Very small, subrectangular to subtriangular. Anterior margin rounded with extremity slightly below mid-height; posterior margin pointed, apex above mid-height. Posterior cardinal angle rounded; anterior cardinal angle pronounced in both valves, slightly more rounded in left valve. Dorsal straight to slightly concave, ventral margin straight to slightly convex. Greatest height at anterior cardinal angle; greatest length above mid-height. Shell surface strongly reticulate, including the anterior and posterior margins. The coarse-meshed, very prominent reticulation is divided by three ribs, which in the median area delimit an approximately circular area. A middorsal – anteromedian rib, a second middorsal – posteromedian rib, and a ventral rib that is strongly curved up in the anterior midventral section towards the anteromedian region. Another rib starting at the anterior cardinal angle parallels the anterior edge of that circular area approximately halfway to the anterior margin. Eye-tubercle absent; internal details not observed.
Procytheropteron catena sp. nov. – 2018 Franz et al., p. 73, plate 4: 4–6.
3 C, 22 RV, 26 LV in sample He19-18–28.
Upper Aalenian, Bradfordensis Zone (Gigantea Subzone) to Concavum Zone; SW Germany.
1 RV in sample He19-18.
Upper Aalenian, Bradfordensis Zone (Gigantea Subzone); SW Germany.
The single (juvenile ?) specimen is only tentatively placed in this genus due to its small size and poor preservation.
3 RV, 4 LV in samples He19-25 – Ha19-3.
Upper Aalenian, Bradfordensis Zone (Gigantea Subzone) to Concavum Zone; SW Germany.
Very small, triangular. Anterior margin rounded with extremity slightly below mid-height; posterior margin pointed, apex below mid-height. Cardinal angles rounded in left valve, cardinal angles pronounced in right valve.
Right valve : Dorsal margin straight, medianly slightly convex, ventral margin slightly convex, medianly partly obscured by a median overhang of the lateral curvature. The punctate shell surface is longitudinally and vertically strongly curved with a ventral overhang. The curvature is concavely recessed in the uppermost area along a sharp oval bend, ending in a weak anteromedian lobe. A narrow anterodorsal depression parallel to the anterior margin is limited by a short, slightly curved frontal rib, ending above mid-height.
Left valve : Dorsal margin strongly convex, otherwise identical to the right valve.
Hinge due to poor preservation not clearly visible, possibly merodont; other internal details not observed.
Genus Procytheropteron Ljubimova, 1955
3 RV, 2 LV in samples He19-22–24 and Ro19-1.
Upper Aalenian, Concavum Zone; SW Germany.
Our specimens resemble Procytheropteron gramanni Brand, 1990 (plate 9: 10) from the Upper Bathonian of NW Germany; they differ in age and in the coarser ornamentation and reticulation.
2 LV in sample He19–24 and from the Geisingen clay pit.
Upper Aalenian, Bradfordensis Zone; SW Germany.
Very small, ovoidal. Anterior margin almost symmetrically rounded; posterior margin pointed, apex at mid-height. Cardinal angles rounded in the left valve.
Dorsal margin straight to slightly convex, ventral margin convex, medianly partly obscured by a median overhang of the lateral curvature. The complete lateral surface is decorated with vertical, broadly rounded ribs. The ribs in the median part of the valve are irregular, interrupted at about mid-height, and offset laterally against each other. The vertical ribs are framed by a curved ventral rib, which is also rounded, and a similar dorsal rib, which almost touch each-other mid-posteriorly.
Internal details not observed.
3 C, 5 RV, 3 LV in samples He19-5–12.
Upper Toarcian to Upper Aalenian; Germany.
2 RV, 3 LV in samples He19-1–22.
Lower Aalenian to Lower Bajocian; SW Germany.
7 C, 10 RV, 9 LV in samples He19-1–13.
Lower to Upper Aalenian, Opalinum to Murchisonae zones; Germany, Switzerland.
1 C in sample He19-15.
Upper Aalenian, Murchisonae Zone; SW Germany.
1 C in sample Ro19-4.
Upper Aalenian, Concavum Zone; SW Germany.
1 RV in sample Ro19-4.
Upper Aalenian, Bradfordensis Zone (Gigantea Subzone) to Concavum Zone; SW Germany.
2 C, 5 RV, 1 LV in samples G08Fr, G12 Fr, G13Fr, He19-6, He19-26–28.
Lower to Upper Aalenian, Opalinum to Concavum zones; SW Germany.
Very small, subrectangular. Anterior margin rounded with extremity slightly below mid-height; posterior margin rounded, apex above mid-height. Cardinal angles rounded in both valves, slightly more pronounced in left valve. Dorsal margin straight, ventral margin slightly convex. The shell surface is smooth, with a number of pits, which are difficult to recognize due to bad preservation. Internal details not observed.
Genus Vernoniella Oertli, 1957
1 C in sample Ro19-5.
Upper Aalenian, Concavum Zone; SW Germany.
Vernoniella ? caytonensis was described from the Blagdeni Subzone in England; our specimen comes from the Concavum Zone and therefore has been tentatively placed in this species.
Genus Asciocythere Swain, 1952
4 C, 3 LV in samples He19-25–26 and Ha19-4.
Upper Aalenian to Lower Bajocian; SW Germany.
We have set Asciocythere in quotation marks, because the generic assignment of this species is doubtful.
2 C, 7 RV, 5 LV in samples He19-21, Mue19-1 and Ro19-1–5.
Upper Aalenian; England, SW Germany.
52 C, 183 RV, 209 LV in samples He19-23–29 and Ro19-1–5.
Upper Aalenian to Lower Bajocian; England, SW Germany.
57 C, 106 RV, 136 LV in samples He19-18–29, Ha19-1–5 and Ro19-1–5.
Lower Aalenian to Lower Bajocian; England, Germany.
36 C, 49 RV, 47 LV in samples He19-13–29, Ha19-1–5 and Ro19-1–5.
Upper Toarcian to Lower Bajocian; Germany, Spain, Switzerland.
4 C, 5 RV, 13 LV in samples Ro19-1–5.
Upper Aalenian, Concavum Zone; SW Germany.
The specimens from the Roschbach section closely resemble Praeschuleridea subtrigona from the Upper Bajocian to Upper Callovian. It is only tentatively placed in this species because of the remarkable difference in age.
118 C, 52 RV, 76 LV in samples He19-2–21, Mue19-1, Ha19-1–3 and Ro19-1–5.
Upper Toarcian to Lower Bajocian; Germany, Spain, Switzerland.
1 C, 2 LV in samples He19-17–25.
Toarcian to Aalenian; Germany, Ireland.
4 C, 2 RV, 4 LV in samples He19-27 and Ha19-5.
Upper Aalenian, Concavum Zone to Early Bajocian; SW Germany.
Medium-sized, subovate. Left valve larger than right valve, overlapping along complete outline. Anterior margin slightly asymmetrically rounded, extremity just below mid-height. Posterior margin triangular, upper margin straight, lower margin convex, the two joining at an angle below mid-height. Dorsal margin convex, ventral margin convex with slight concavity in front of mid-length in the right valve. Anterior cardinal angle rounded, posterior cardinal angle sloping straight to the posterior margin. Valve ventrolaterally swollen. Small-sized pits irregularly distributed over the anterior valve surface, significantly denser in the posterior third. A narrow channel with densely arranged pits parallels the anterior margin. Anteroventrally and posteroventrally there is a row of finest denticles.
The partly broken (? paleohemimerodont) hinge shows terminal serrated teeth and remains of teeth in the median hinge area of the right valve.
Genus Southcavea Bate, 1964
3 C, 7 RV, 4 LV in samples He19-18–25 and Ro19-1–2.
Upper Aalenian, Bradfordensis Zone (Gigantea Subzone); SW Germany.
1 RV, 1 LV in sample He19-18.
Upper Aalenian, Bradfordensis Zone (Gigantea Subzone) to Lower Bajocian; England, southwest Germany.
20 C, 29 RV, 27 LV in samples He19-24–29, Ha19-4–5 and Ro19-1–3.
Upper Aalenian, Concavum Zone to Early Bajocian; SW Germany.
1 LV in sample He19-16.
Upper Aalenian, Murchisonae Zone; SW Germany.
This specimen resembles Pleurocythere kirtonensis in the arrangement of the ribs. In contrast to P. kirtonensis the ribs are broad and rounded. Possibly the median rib touches the ventral rib anteroventrally. More material is required for clarification.
1 RV, 1 LV in sample He19-1.
Lower Aalenian, Opalinum Zone; SW Germany.
The two specimens may represent an ancestor of the genus Pleurocythere.
Genus Acrocythere Neale, 1960
4 C, 2 RV, 4 LV in samples He19-1–12.
Lower Aalenian, Opalinum Zone; Germany, Switzerland.
3 LV in samples He19-18 and He19-27.
Upper Aalenian, Bradfordensis Zone (Gigantea Subzone) to Concavum Zone; Germany.
In addition to the differentiation from Acrocythere pumila in Plumhoff, 1963, it should be noted that the reticulation between the median rib and the ventral rib in the posterior section is alternating here, whereas it is clearly linear in A. pumila.
1 LV in sample He19-15.
Upper Aalenian, Murchisonae Zone; SW Germany.
22 C, 15 RV, 18 LV in samples He19-15–28, Mue19-1 and Ro19-4.
Upper Aalenian, Murchisonae to Concavum zones; SW Germany.
30 C, 43 RV, 36 LV in samples He19-24–28 and Ro 1–3.
Upper Aalenian; Germany.
1 C in sample He19-18.
Aalenian, Bradfordensis Zone; SW Germany.
1 C, 6 RV, 6 LV in sample He19-17.
Upper Aalenian, Bradfordensis Zone; SW Germany.
11 C, 34 RV, 34 LV in samples Ha19-4–5.
Lower Bajocian; SW Germany. Progonocythere triangulata is the index species of the Triangulata ostracod Subzone (
1 C, 4 RV, 16 LV in samples He19-23–29.
Upper Aalenian to Lower Bajocian, Concavum to Discites zones; SW Germany.
6 C, 18 RV, 22 LV in samples He19-14–18, Ha19-6, Lin 18-4, Mue19-1 and Ro19-1–5.
Upper Toarcian to Upper Aalenian; France, Germany, Russia, Spain, Switzerland.
4 C, 76 RV, 109 LV in samples He19-21–28 and Ro19-1–5.
Upper Aalenian to Lower Bajocian, Concavum to Discites zones; SW Germany.
2 C, 1 RV in sample He19-9.
Lower Toarcian to Lower Bajocian; England, France, Germany, Ireland, Portugal, Russia, Spain, N Switzerland.
9 C, 14 RV, 10 LV in samples Mue19-1 and Ro19-1–5.
Upper Aalenian to Lower Bajocian; SW Germany.
5 RV in samples Ha19-4–5.
Early Bajocian; England, France, Germany, N Switzerland.
9 RV, 8 LV in samples He19-25–26, Mue19-1, Ha19-5 and Ro19-3–5.
Upper Aalenian to Early Bajocian, Concavum to Discites zones; SW Germany.
5 RV, 5 LV in samples He19-14–17 and Ro19-2.
Lower to Upper Aalenian, Opalinum Zone (“Comptum” Subzone) to Bradfordensis Zone; SW Germany.
Anterior margin broadly rounded, accompanied by a flat marginal bulge. The dorsal margin slightly convex, with the greatest height in front of midlength of the valve. Posterior end flat, with narrowly rounded posterior margin. Ventral margin obscured by the the overhanging ventro-lateral curvature. The central part of the valve is ventrally strongly inflated, and clearly set off against the anterior and posterior ends. Remnants of two ventral ribs are visible parallel to the ventral margin. The remaining part of the valve shows only weak hints of a very fine, irregular reticulation.
1 RV in sample He19-14.
Toarcian to Lower Aalenian; England, SW Germany.
Genus Fuhrbergiella Brand & Malz, 1962
2 LV in samples Ha19-4–5.
Lower Bajocian, Discites Zone; Germany.
Genus Minyocythere
5 C, 3 RV, 5 LV in samples Mue19-1 and Ro 3–5.
Upper Aalenian to Lower Bajocian, Concavum to Humphriesianum zones; Germany.
6 C, 30 RV, 24 LV in samples He19-23–28, Mue19-1 and Ro19-1–3.
Upper Aalenian, Bradfordensis Zone (Gigantea Subzone) to ? Lower Bajocian; England, France, Germany, Luxembourg.
2 RV in samples He19-2 and He19-12.
Aalenian to Bajocian; Argentina, SW Germany.
1 RV in sample He19-17.
Lower to Upper Aalenian, Opalinum to Bradfordensis zones; SW Germany, N Switzerland.
2 RV in samples He19-2 and He19-5.
Lower Aalenian, Opalinum Zone; SW Germany.
4 RV, 1 LV in samples He19-3–27.
Lower to Upper Aalenian, Opalinum to Concavum zones; SW Germany, N Switzerland.
Gen. et sp. indet. I. – 2019 Dietze et al., pl. 11, fig. 13.
4 RV, 1 LV in sample He19-22; one further RV from Thanheim.
Upper Aalenian, Bradfordensis Zone (Gigantea Subzone) to Concavum Zone; SW Germany.
2 RV in samples He19-5–12.
Lower Aalenian, Opalinum Zone; SW Germany.
1 RV, 1 LV in samples He19-17–18.
Upper Aalenian, Bradfordensis Zone; SW Germany.
1 RV, 2 LV in samples He19-12–15.
Lower to Upper Aalenian, Opalinum to Murchisonae zones; SW Germany.
1 LV in sample He19-8.
Lower Aalenian, Opalinum Zone; SW Germany.
1 LV in sample He19-16.
Upper Aalenian, Murchisonae Zone; SW Germany.
Length | Height | Width | |
---|---|---|---|
Holotype | 0.516 mm | 0.338 mm | |
Paratype | 0.556 mm | 0.364 mm | |
Paratype | 0.557 mm | 0.222 mm | |
Paratype | 0.555 mm | 0.363 mm |
Length | Height | Width | |
---|---|---|---|
Holotype | 0.306 mm | 0.164 mm | |
Paratype | 0.292 mm | 0.155 mm | |
Paratype | 0.318 mm | 0.135 mm |
The ammonite fauna of the Upper Aalenian of SW Germany is dominated by members of the subfamily Graphoceratinae Buckman, 1905, besides rare Hammatoceratinae Buckman, 1887. The Graphoceratinae originate in the subfamily Leioceratinae Spath, 1936. The family Graphoceratidae itself descends from the Upper Toarcian genus Pleydellia Buckman, 1899 (Grammoceratinae Buckman, 1905 within the family Hildoceratidae Hyatt, 1867) (
The evolution within the Graphoceratidae occurred in a chronocline ranging from the lowermost Aalenian (Opalinum Zone, Opalinum Subzone) to the lowermost Bajocian (Discites Zone), with an immense morphological variability within each of the temporally succeeding faunas. In this plexus, individual morphologies sometimes have a long temporal range, whereas the variability of the succeeding faunas as a whole shifts – that is the reason why we can distinguish and define faunal biohorizons. Faunal biohorizons reflect the change of variation in the course of evolution of ammonites, here of Graphoceratidae (e.g.,
In the literature, there are many attempts to classify the plexus of the Graphoceratidae into categories (families, subfamilies, morphogenera, morphospecies). The results of these attempts and the erection of new genera and species depended often by chance, depending on where the author had material from, often without any accurate stratigraphy. The great number of genera and species described in the literature (e.g.
We here determined the ammonites conventionally as morphogenera and morphospecies, since we do not have enough material to describe these ammonites chrono- or (palaeo)biospecifically. However, it is most likely that all graphoceratid ammonites from the cavatum horizon described here represent a single palaeobiospecies.
4.2.1 Family Graphoceratidae Buckman, 1905, Subfamilies Leioceratinae Spath, 1936 and Graphoceratinae Buckman, 1905
Leioceras opalinum [m] and L. opaliniforme [M] occur about 10 m below the “Wasserfallschichten” in the Heiligenbach creek.
The ammonites from the “Comptum” Subzone are represented by L. “comptum”, L. crassicostatum, L. evolutum, L. paucicostatum and L. striatum. They are significantly smaller than the L. “comptum” faunas from the Wochenberg and Gosheim (western Swabian Alb) which comprise more evolute morphs. These ammonites will be described later in detail.
A single Brasilia bradfordensis (Fig.
The graphoceratid fauna of the Inopernabank (Bradfordensis Zone, Gigantea Subzone) and from the Konglomeratbank to the Rostrote Kalkbank (Concavum Zone, Concavum Subzone) is characterized by the predominance of the morphogenus Graphoceras; less common are representatives of the morphogenus Brasilia and a substantial number of ammonites with various combinations of both morphogenera (cf.
We here follow
4.2.2 Family Hammatoceratidae Buckman, 1887, Subfamily Hammatoceratinae Buckman, 1887
A single record from the Inopernabank (Fig.
5.1.1 Opalinum Zone
Pygmaea-pumila faunal assemblage (
The ostracod assemblage consists of 360 individuals (average of 30 individuals per sample) representing 34 species. The assemblage is characterized by Praeschuleridea ventriosa, Aphelocythere pygmaea, Metacytheropteron opalinum, Acrocythere pumila, Eucytherura transversiplicata, Euc. michelseni, Cardobairdia tesakovae, Eucytherura sp. 1 Franz et al., Euc. sp. 3 Franz et al., and Cytheropterina cribra.
The zonal index species Aphelocythere kuhni (
In samples He19-7–12, eight species have their last occurrences in this faunal assemblage: Acrocythere pumila, Procytherura euglyphea, Eucytherura plumhoffi, Ostracode A Ballent, Eucytherura foveolata, Cardobairdia tesakovae, Metacytheropteron opalinum, and Eucytherura sp. 1 Franz et al.
5.1.2 “Comptum” Subzone (samples He19-13–14)
The stratigraphical significance of the ostracod assemblage from the “Comptum” Subzone is rather limited (8 species, represented by only 65 specimens). The assemblage is characterized by the extinction of the previously typical species Aphelocythere pygmaea, Acrocythere pumila, Procytherura euglyphea, Proc. celtica, Eucytherura plumhoffi, Euc. foveolata, Euc. sp. 1 Franz et al., Metacytheropteron opalinum, and Cardobairdia tesakovae. Aphelocythere pygmaea has its last appearance (very rare) in the claystones directly above the Comptumbank. Only Cytherella apostolescui appears for the first time, like in the Geisingen clay pit (
Dominant species include Praeschuleridea ventriosa, Pr. punctulata and Kinkelinella (K.) fischeri.
5.1.3 Murchisonae Zone (samples He19-15–16)
The samples from the clays above the “Doppelbank” 20 + 21 yielded 126 specimens of 17 species, 12 of which were found in single specimens. Dominant species are Praeschuleridea ventriosa, Pr. punctulata and Homocytheridea sp. 1. Nine species are new; most important are Homocytheridea sp. 1, Bythoceratina (Praebythoceratina) sp. 1, Eucytherura sp. 3 Franz et al. and, to a minor degree, the very rare Pleurocythere sp. 1. The still undescribed Gen. et sp. indet. 10 Franz has its last appearance. Homocytheridea sp. 2, Procytherura aff. serangodes, Aphelocythere cf. pygmaea, Pleurocythere sp. 1 and Gen. et sp. indet. 12 were found only in single specimens in this assemblage.
Homocytheridea sp. 1 differs from Homocytheridea cf. punctulata from the Concavum Zone in the Geisingen clay pit. The stratigraphic distribution of Homocytheridea in the Upper Aalenian can be clarified only after investigation of further material.
5.1.4 Bradfordensis Zone, Bradfordensis Subzone (sample He19-17)
In this sample, we found 12 species (only 25 specimens), the majority of which are again represented by single specimens. Among the newly appearing species the solely abundant Progonocythere scutula (13 specimens) is particularly noteworthy. It was first described by
5.1.5 Bradfordensis Zone, Gigantea Subzone (samples He19-18–21)
The stratigraphical significance of this assemblage (35 species, represented by 169 specimens) is restricted. Eighteen species occur for the first time respectively reoccur in this part of the section: Praeschuleridea ornata, Pr. ventriosa, Balowella catena, Cytherelloidea lordi, Pleurocythere kirtonensis and rare Kinkelinella levata and Eocytheridea elongata in the uppermost sample. Dominant species are Praeschuleridea ornata and Pr. ventriosa, which alone account for > 22% of the total assemblage, Cytheropterina bicuneata, Praeschuleridea punctulata and Balowella catena. Eucytherura michelseni, Eucyth. sp. 3 Franz et al., Cytherelloidea cf. catenulata and Gen. et sp. indet. 9 have their last appearances in this section. Cytherelloidea lordi, Pleurocythere kirtonensis, Aaleniella compressa and Eucytherura sp. 5 Franz were found in this assemblage only.
As already observed in Geisingen (
5.1.6 Concavum Zone (samples He19-21–28, Mue19-1, Ha19-1–3, Ro19-3–5)
The Concavum-Zone comprises the claystones immediately below and above the Inopernabank up to the Sowerbyi-Oolith. Since the claystones above the Rostrote Kalkbank are not exposed along the Heiligenbach creek, their basal part was sampled at the Mühlbächle creek in Jungingen and, for comparison purposes, at the Roschbach in Balingen-Zillhausen. The 14 samples obtained there show ostracod (and foraminifers) assemblages relatively rich in species and individuals. The upper half of these claystones and the basal Wedelsandstein Formation were sampled in the Hausterberg section. The claystones in this level are fine sandy and very poor in microfossils. In some samples only one foraminiferal and one ostracod species were found in small (foram.) to very small (ostr.) numbers.
This assemblage (including the samples from the Roschbach valley) comprises 2,365 specimens from 58 species, 34 of which appear for the first time in this section. Dominant species are Cytherella apostolescui, Praeschuleridea ornata and the newly appearing Eocytheridea lacunosa and Camptocythere pusilla. The still persisting Praeschuleridea ventriosa, Pr. punctulata, Balowella catena, Cytheropterina bicuneata, Eucytherura eberti and Bythoceratina (Praebyth.) sp. 1 are common as well. Of 34 species appearing here for the first time, the following ones are somewhat more common and useful for stratigraphic purposes (in the order of their first occurrence in this section): Eocytheridea lacunosa, Plumhofficythere clavatoides, Kinkelinella (Kink.) adunca, Camptocythere pusilla, Pleurocythere ohmerti, Kinkelinella (Kink.) sp. B Ohmert, Cytheropterina crassicostata, Cyth. alacostata, Kinkelinella (Kink.) cf. sermoisensis, Praeschuleridea cf. subtrigona, and Minyocythere tuberculata.
The two species of Cytheropterina are very conspicuous, but Cytheropterina alacostata is often represented by very small specimens.
Camptocythere pusilla, the index species of the Pusilla Ostracod Zone (
Eucytherura eberti sp. nov., which has been found in rare specimens from the uppermost Opalinum Zone upwards, has its acme at this level. A number of further, mostly small species appear here for the first time. Although they are partly very conspicuous (e.g., ? Cytheropteron sp. 1, Eucytherura sp. 10), they are rather unsuitable for stratigraphic purposes due to their scarcity. Additionally, some of these rare species occur earlier elsewhere. A range chart for the Achdorf Formation is given in Appendix 2.
Bajocian
5.1.7 Discites Zone (samples Ha19-4–6)
The appearance of Kinkelinella (Ekt.) triangula and Progonocythere triangulata, together with Cytherelloidea cf. cadomensis and rare Fuhrbergiella horrida bicostata in this assemblage (374 specimens) clearly indicates the base of the Triangula Ostracod Zone, Triangulata Ostracod Subzone (= Discites Zone;
Aalenian
5.2.1 Opalinum Zone
Opalinum and “Comptum” subzones: The strata of the Opalinum Zone were not in the focus of this investigation. However, the Opalinum Subzone reaches at least up to the “Wasserfallschichten” in the area. About 8 m above the “Zopfplatten” of the Heiligenbach section the “Comptum” Subzone is verified by numerous small-sized ammonites of the L. “comptum” – L. evolutum group.
5.5.2 Murchisonae Zone
At present, we cannot confirm strata of this age with ammonites.
5.2.3 Bradfordensis Zone
Bradfordensis Subzone: Beds 20–22 in the Roschbach section and bed 2 of the Mühlbächle section belong to the Bradfordensis Subzone. Ammonites are Brasilia bradfordensis and Staufenia staufensis.
Gigantea Subzone: For the moment, we place the ammonite fauna of the Inopernabank bed into the uppermost Gigantea Subzone. The graphoceratid fauna of this bed itself is not diagnostic enough to decide definitely, if this bed should be placed in the youngest Gigantea Subzone (younger than decipiformis biohorizon) or in the oldest Concavum Subzone (older than cavatum biohorizon). However, the single Planammatoceras sp. is very close to some of the hammatoceratids from the decipiformis biohorizon (Gigantea Subzone) of Geisingen, but very different from the hammatoceratids of the cavatum biohorizon (Concavum Subzone). Hence, we tentatively assign these beds in the Gigantea Subzone. Ammonites: Brasilia decipiens, Graphoceras cavatum, G. cf. caduciferum, G. aff. fallax, Ludwigella tenuis, L. aff. tenuis, L. attenuata, L. attracta, Planammatoceras sp.
5.2.4 Concavum Zone
Concavum Subzone (cavatum horizon): The Calceolabank (Roschbach: Bed 28, Mühlbächle: Bed 14, Heiligenbach: Bed 45, Hanneswiesle: Bed 4) belongs to the cavatum biohorizon of the Concavum Subzone. The fauna is a mixture of Brasilia spp., the dominant Graphoceras spp. and transitional morphologies besides Euaptetoceras infernense sensu Buckman. Ammonites: Brasilia decipiens, B. cf. decipiens, B. aff. decipiens, B. cf. decipiformis, Graphoceras cavatum, G. cf. cavatum, G. cf. concavum, G. fallax, G. aff. magnum, G. decorum, G. pulchrum, G. formosum, Ludwigella arcitenens, L. attracta, L. micra, L. cornu, Euaptetoceras cf. euaptetum, E. infernense sensu Buckman, E. cf. kochi.
Formosum Subzone: There is no evidence for this subzone in the Zollernalb.
Bajocian
5.2.5 Discites Zone
The Sowerbyi-Oolith bed belongs to the Discites Zone (see
(1) Cardobairdia tesakovae Franz et al., SMNS 70521/1, LV, L: 0.426 mm; sample He19-6; (2) Patellacythere cf. vulsa, SMNS 70521/2, LV, L: 0.51 mm; sample He19-9; (3) Procytherura celtica Ainsworth, SMNS 70521/3, RV, L: 0.301 mm; sample He19-12. (4, 5) Procytherura euglyphea Ainsworth, (4) SMNS 70521/4, RV, L: 0.320 mm; sample He19-1; (5) SMNS 70521/5, LV, L: 0.327 mm; sample He19-12. (6, 7) Procytherura multicostata Ainsworth, (6) SMNS 70521/6, LV, L: 0.336 mm; sample He19-9; (7) SMNS 70521/7, RV, L: 0.319 mm; sample He19-16. (8) Procytherura sp. 2 Franz et al., SMNS 70521/8, RV, L: 0.325 mm; He19-8. (9–11) Eucytherura eberti sp. nov., (9) holotype, SMNS 70521/9, C, left view, L: 0.306 mm; sample He19-18; (10) Paratype, SMNS 70521/10, C, right view, L: 0.292 mm; sample He19-21; (11) paratype, SMNS 70521/11, C, dorsal view, L: 0.318 mm; sample He19-26. (12–14) Eucytherura foveolata sp. nov., (12) holotype, SMNS 70521/12, C, left view, L: 0.327 mm; sample G08Fr; (13) paratype, SMNS 70521/13, C, right view, L: 0.318 mm; sample G12Fr; (14) paratype, SMNS 70521/14, C, right view (detail), image width: 0.07 mm; sample G12Fr; (15) Eucytherura liassica Bate and Coleman, SMNS 70521/15, LV, L: 0.304 mm; sample He19-17. (16) Eucytherura michelseni (Finger), SMNS 70521/16, LV, L: 0.324 mm; sample He19-18. (1–6, 8, 12–14) Opalinuston Formation, Lower Aalenian, Opalinum Zone; (7, 9–11, 15–16) Achdorf Formation, Upper Aalenian, (7) Murchisonae Zone, (15) Bradfordensis Zone (Bradfordensis Subzone), (9, 10, 16) Bradfordensis Zone (Gigantea Subzone), (11) Concavum Zone. Scale bars (if not indicated otherwise): 20 μm.
(1) Eucytherura plumhoffi Tesakova, SMNS 70521/17, C, left view, L: 0.309 mm; sample He19-7. (2) Eucytherura transversiplicata (Bate and Coleman), SMNS 70521/18, LV, L: 0.316 mm; sample He19-3. (3) Eucytherura sp. 1 Franz et al., SMNS 70521/19, RV, L: 0.320 mm; sample He19-12. (4) Eucytherura sp. 3 Franz, SMNS 70521/20, C, right view, L: 0.300 mm; sample He19-18; (5) Aphelocythere dilgeri Franz et al., SMNS 70521/21, RV, L: 0.460 mm; sample He19-18. (6) Aphelocythere pygmaea Plumhoff, SMNS 70521/22, C, right view, L: 0.343 mm; sample He19-12; (7) ? Aphelocythere sp. 1, SMNS 70423/119, C, right view, L: 0.308 mm; sample G08Fr; (8) ? Pleurocythere sp., SMNS 70521/23, LV, L: 0.354 mm; sample He19-1. (9) Acrocythere pumila Plumhoff, SMNS 70521/24, LV, L: 0.343 mm; He19-12. (10) Praeschuleridea ventriosa (Fischer in Plumhoff), SMNS 70521/25, LV, L: 0.650 mm; sample Mue19-1; (11) Kinkelinella (Kink.) sermoisensis (Apostolescu), SMNS 70521/26, LV, L: 0.656 mm; sample He19-9; (12) aff. Ostracode A Ballent, SMNS 70521/27, RV, L: 0.290 mm; sample He19-2. (13) Gen. et sp. indet. 3, Franz et al., SMNS 70521/28, RV, L: 0.342 mm; sample He19-5; (14) Gen. et sp. indet. 5 Franz et al., SMNS 70521/29, RV, L: 0.310 mm; He19-18; (15) Gen. et sp. indet. 8 Franz, SMNS 70521/30, RV, L: 0.280 mm; sample He19-12. (16) Gen. et sp. indet. 10, SMNS 70521/31, LV, L: 0.300 mm; sample He19-12. (17) Gen. et sp. indet. 11, SMNS 70521/32, LV, L: 0.324 mm; sample He19-8. (1–3, 6–8, 10–12, 15–17) Opalinuston Formation, Lower Aalenian, Opalinum Zone; (4–5, 9, 14) Achdorf Formation, Upper Aalenian, (4–5, 14) Bradfordensis Zone (Gigantea Subzone), (9) Concavum Zone. Scale bars (if not indicated otherwise): 20 μm.
(1) Cytherella apostolescui Ainsworth, SMNS 70521/33, RV, L: 0.793 mm; sample He19-27. (2) Cytherelloidea cf. catenulata (Jones and Sherborn), SMNS 70521/34, LV, L: 0.438 mm; sample He19-17. (3) Bythoceratina (Praebyth.) sp. 1, SMNS 70521/35, RV, L: 0.416 mm; sample He19-18. (4) Procytherura cf. serangodes Ballent and Whatley, SMNS 70521/36, C, right view, L: 0.331 mm; sample He19-15; (5) Praeschuleridea punctulata (Plumhoff), SMNS 70521/37, C, right view, L: 0.606 mm; sample He19-15. (6) Praeschuleridea sp. A Ainsworth, SMNS 70521/38, LV, L: 0.733 mm; sample He19-17; (7) Pleurocythere sp. 1, SMNS 70521/39, RV, L: 0.585 mm; sample He19-16. (8) Homocytheridea sp. 1, SMNS 70521/40, LV, L: 0.707 mm; He19-15. (9) Homocytheridea sp. 2, SMNS 70521/41, RV, L: 750 mm; sample Mue19-1; (10) Progonocythere scutula Franz et al., SMNS 70521/42, RV, L: 0.464 mm; sample He19-17; (11) Kinkelinella (Kink.) fischeri Malz, SMNS 70521/43, C, left view, L: 0.412 mm; sample Lin18-4. (12) Kinkelinella sp. 2, SMNS 70521/44, RV, L: 0.444 mm; sample He19-17; (13) Ektyphocythere aff. anterocosta Boomer, SMNS 70521/45, RV, L: 0.281 mm; sample He19-14; (14) Gen. et sp. 9 Tesakova, SMNS 70521/46, RV, L: 0.296 mm; He19-17; (15) Gen. et sp. indet. 9, SMNS 70521/47, LV, L: 0.235 mm; sample He19-18. (16) Gen. et sp. indet. 12, SMNS 70521/48, LV, L: 0.306 mm; sample He19-16. Achdorf Formation (13) Opalinum Zone, (“Comptum” Subzone), (4–5, 7–8, 16) Murchisonae Zone, (2, 6, 10, 12, 14) Bradfordensis Zone (Bradfordensis Subzone), (3, 15) Bradfordensis Zone (Gigantea Subzone), (1, 7) Concavum Zone. Scale bars (if not indicated otherwise): 20 μm.
(1) Cytherelloidea lordi Ainsworth, SMNS 70521/49, C, right view, L: 0.688 mm; sample He19-19. (2) Bairdiacypris triangularis Ainsworth, SMNS 70521/50, C, right view, L: 0.309 mm; sample He19-19. (3) Macrocypris aequabilis Oertli, SMNS 70521/51, C, left view, L: 0.349 mm; sample He19-21. (4) Eucytherura cf. parairregularis Brand, SMNS 70521/52, C, right view, L: 0.281 mm; sample He19-19; (5) Eucytherura cf. yunga Ballent and Whatley, SMNS 70521/53, RV, L: 0.304 mm; sample He19-27. (6) Eucytherura sp. 5 Franz, SMNS 70521/54, RV, L: 0.295 mm; sample G11Fr; (7) Eucytherura sp. 11 Franz, SMNS 70521/55, RV, L: 0.327 mm; sample He19-25. (8) Balowella catena (Franz et al.), SMNS 70521/56, RV, L: 0.308 mm; sample He19-24. (9) Praeschuleridea ornata (Bate), SMNS 70521/57, RV, L: 0.578 mm; sample He19-21; (10, 11) ? Southcavea sp., (10) SMNS 70521/58, LV, L: 0.315 mm; (11) SMNS 70521/59, RV, L: 0.368 mm; sample He19-24; (12) Pleurocythere kirtonensis Bate, SMNS 70521/60, RV, L: 0.597 mm; sample He19-18. (13) Acrocythere aff. pumila Plumhoff, SMNS 70521/61, LV, L: 0.406 mm; sample He19-27; (6) Opalinuston Formation, Lower Aalenian, Opalinum Zone, (1–5, 7–13) Achdorf Formation, Upper Aalenian (1–4, 9, 12) Bradfordensis Zone (Gigantea Subzone), (5, 7–8, 10–11, 13) Concavum Zone. Scale bars (if not indicated otherwise): 20 μm.
(1) Polycope cf. riegrafi Brand, SMNS 70521/62, C, right view, L: 0.345 mm; sample He19-27. (2) ? Liasina cylindrica Ainsworth, SMNS 70521/63, RV, L: 0.412 mm; sample Lin18-1. (3) Cardobairdia toarcensis Ainsworth, SMNS 70521/64, LV, L: 545 mm; sample He19-26. (4) Macrocypris ? liassica Bate and Coleman, SMNS 70521/65, C, right view, L: 0.750 mm; sample He19-27; (5) Patellacythere paravulsa cf. tenuis Brand, SMNS 70521/66, LV, L: 0.522 mm; sample He19-27. (6) Patellacythere ungulina (Triebel and Bartenstein), SMNS 70521/67, LV, L: 0.405; sample Mue19-1; (7) “Monoceratina aff. posterocarinata Brand, SMNS 70521/68, C, right view, L: 0.324 mm; sample He19-21. (8) Tanycythere posteroelongata Cabral et al., SMNS 70521/69, C, right view, L: 0.676 mm; He19-27. (9) Cytheropterina alacostata Franz et al., SMNS 70521/70, LV, L: 0.368 mm; sample He19-27; (10–13) Cytheropterina crassicostata sp. nov., (10) holotype, SMNS 70521/71, RV, L: 0.516 mm; sample He19-27; (11) paratype, SMNS 70521/72, LV, L: 0.556 mm; sample He19-26, (12) paratype, SMNS 70521/73, RV, ventral view, L: 0.557 mm; sample He19-27; (13) paratype, SMNS 70521/74, LV, inner view, L: 0.555 mm; sample Ro19-4; (14) Procytherura sp. 5, SMNS 70521/75, RV, L: 0.363 mm; He19-24; (15) Eucytherura aff. yunga Ballent and Whatley, SMNS 70521/76, LV, L: 0.312 mm; sample He19-27. (16) Eucytherura sp. B Boomer and Ballent, SMNS 70521/77, RV, L: 0.277 mm; sample He19-25. (17, 18) Eucytherura sp. 10, (17) SMNS 70521/78, LV, L: 0.392; sample He19-25, (18) SMNS 70521/79, RV, L: 0.278 mm; sample He19-24. Achdorf Formation, Upper Aalenian, Concavum Zone. Scale bars (if not indicated otherwise): 20 μm.
(1) Balowella catena (Franz et al.), SMNS 70521/80, C, right view, L: 0.329 mm; sample He19-18. (2, 3); ? Cytheropteron sp. 1, (2) SMNS 70521/81, LV, L: 0.322 mm; sample He19-27; (3) SMNS 70521/82, RV, L: 0.355 mm; sample He19-27. (4, 5) Procytheropteron aff. gramanni Brand, (4) SMNS 70521/83, LV, L: 0.373 mm; sample He19-26; (5) SMNS 70521/84, RV, L: 0.305 mm; sample He19-22. (6) Procytheropteron sp. 1 Franz et al., SMNS 70423/66, LV, L: 0.322 mm; sample G20b; (7) Aphelocythere recta Ohmert, SMNS 70521/85, C, right view, L: 0.460 mm; sample Ro19-4. (8) Aphelocythere aff. recta, SMNS 70521/86, C, right view, L: 0.466 mm; sample Ro19-4. (9) Aphelocythere sp. 1, SMNS 70521/87, RV, L: 0.630 mm; sample He19-27; (10) “Asciocythere” sp., SMNS 70521/88, RV, L: 436 mm; sample He19-26. (11) Eocytheridea elongata Bate, SMNS 70521/89, RV, L: 0.573 mm; sample He19-21. (12) Eocytheridea lacunosa Bate, SMNS 70521/90, RV, L: 0.705 mm; sample He19-25; (13, 14) Praeschuleridea cf. subtrigona, (13) SMNS 70521/91, C, right view, L: 0.512 mm; sample Ro19-5; (14) SMNS 70521/92, RV, inner view, L: 0.512 mm; sample Ro19-5; (15–17) Praeschuleridea sp. 1, (15) SMNS 70521/93, C, right view, L: 0.490 mm; sample He19-27, (16) SMNS 70521/93, C, right view, (detail); (17) SMNS 70521/94, RV, L: 0.620 mm; L: 0.620 mm; sample He19-27. (18) Pleurocythere ohmerti Franz et al., SMNS 70521/94, LV, L: 0.479 mm; sample Tst. 38-1988 (= He19-27). Achdorf Formation, Upper Aalenian, (1, 6) Bradfordensis Zone (Gigantea Subzone), (2–5, 7–18) Concavum Zone. Scale bars (if not indicated otherwise): 20 μm.
(1) Camptocythere pusilla Plumhoff, SMNS 70521/95, RV, L: 0.446 mm; sample He19-24; (2) Kinkelinella (K. adunca Malz, SMNS 70521/96, LV, L: 0.598 mm; sample He19-24. (3) Kinkelinella (Kink.) levata Ohmert, SMNS 70521/97, RV, L: 0.636 mm; sample He19-27; (4) Kinkelinella (Kink..) cf. sermoisensis, SMNS 70521/98, LV, L: 0.640 mm; sample Mue19-1. (5) Kinkelinella sp. B Ohmert, SMNS 70521/99, LV, L: 0.623 mm; sample Ha19-5; (6) Minyocythere tuberculata (Luppold), SMNS 70521/100, RV, L: 0.400 mm; sample Mue19-1. (7) Plumhofficythere clavatoides Luppold, SMNS 70521/101, LV, L: 0.408 mm; sample He19-27; (8, 9) Gen. et sp. 7, (8) SMNS 70521/102, RV, L: 0.306 mm; sample He19-22; (9) SMNS 70521/103, RV, L: 0.291 mm, sample He19-22. (10) Vernoniella ? caytonensis Bate, SMNS 70521/104, C, left view, L: 0.535 mm; sample Ro19-5. (11) Progonocythere triangulata Braun in Ohmert, SMNS 70521/105, RV, L: 0.712 mm; sample Ha19-4; (12) Kinkelinella (Ekt.) triangula Brand, SMNS 70521/106, RV, L: 0.523 mm; sample Ha19-4. (13) Fuhrbergiella horrida bicostata Brand and Malz, SMNS 70521/107, LV, L: 0.560 mm; sample Ha19-5. Achdorf Formation, Upper Aalenian, (5) Bradfordensis Zone (Gigantea Subzone), (1–4, 6–11) Concavum Zone. Scale bars (if not indicated otherwise): 20 μm.
(1a, b) Brasilia decipiens (Buckman) [M], SMNS 70519/7. (2a, b, 9a, b) Graphoceras cavatum (Buckman) [M], (2) SMNS 70519/8, (9) SMNS 70519/9. (3) G. aff. fallax (Buckman) [M], SMNS 70519/10. (4) Ludwigella tenuis (Buckman) [m], SMNS 70519/11. (5) L. aff. tenuis (Buckman) [m], SMNS 70519/12. (6) Ludwigella attenuata (Buckman) [m], SMNS 70519/13. (7, 8) L. attracta (Buckman) [m], (7) SMNS 70519/14, (8) SMNS 70519/15. (1a–8) Jungingen (Starzel); Achdorf Formation, Bed 4, Upper Aalenian, Bradfordensis Zone (Gigantea Subzone). Asterisk marks beginning of the bodychamber. Scale bar: 5 cm.
(1a–c) Planammatoceras sp. [M], SMNS 70519/16. Jungingen (Starzel); Achdorf Formation, Bed 4, Upper Aalenian, Bradfordensis Zone (Gigantea Subzone). (2a, b) Euaptetoceras infernense sensu Buckman [M] (2b: innermost whorls from reverse flank), SMNS 70519/17. Hechingen-Beuren (Hanneswiesle); Achdorf Formation, Bed 4 [Calceolabank], Upper Aalenian, Concavum Zone (Concavum Subzone), cavatum biohorizon. Asterisk marks beginning of the bodychamber. Scale bar: 5 cm.
(1a, b) G. cf. concavum (Sowerby) [M], with Propeamussium pumilum (Lamarck), SMNS 70519/18. (2) G. decorum Buckman [M], SMNS 70519/19. (3a, b) G. aff. apertum (Buckman) [M], SMNS 70519/20. (4a, b) G. cf. pulchrum (Buckman) [M], SMNS 70519/21. (5a, b) G. pulchrum (Buckman) [M], SMNS 70519/22. (6a, b) Ludwigella arcitenens (Buckman) [m], SMNS 70519/23. (1a–6b) Hechingen-Beuren (Hanneswiesle); Achdorf Formation, Bed 4 [Calceolabank], Upper Aalenian, Concavum Zone (Concavum Subzone), cavatum biohorizon. Asterisk marks beginning of the bodychamber. Scale bar: 5 cm.
(1, 4) Graphoceras cf. concavum (Sowerby) [M], (1) SMNS 70519/24, (4) SMNS 70519/25. (2a, b, 5a, b) Brasilia cf. decipiformis Dietze et al. [M], (2) SMNS 70519/26, (5) SMNS 70519/27. (3a, b) Ludwigella arcitenens (Buckman) [m], SMNS 70519/28. (1–5b) Balingen-Zillhausen (Roschbach), Upper Aalenian, Achdorf Formation; Concavum Zone (Concavum Subzone); (3a, b) Bed 26; (1–2b, 4–5b) Bed 28 [Calceolabank], Upper Aalenian, Concavum Zone (Concavum Subzone), cavatum biohorizon. Asterisk marks beginning of the bodychamber. Scale bar: 5 cm.
(1a, b) Graphoceras cf. caduciferum (Buckman) [M], Bed 40 [Inopernabank], Bradfordensis Zone, (Gigantea Subzone), SMNS 70519/29. (2) Graphoceras sp., Bed 45 [Konglomeratbank], Bradfordensis Zone, (Gigantea Subzone), SMNS 70519/30. (3) Ludwigella arcitenens (Buckman) [m], Bed 45 [Calceolabank], SMNS 70519/31. (4) Euaptetoceras infernense sensu Buckman [M], Bed 45 [Calceolabank], SMNS 70519/32. (5) L. sp. [m], Bed 45 [Calceolabank], SMNS 70519/33. (3–5) Upper Aalenian, Concavum Zone (Concavum Subzone), cavatum biohorizon. (1a–5) Hechingen-Beuren (Heiligenbach), Achdorf Formation. Asterisk marks beginning of the bodychamber. Scale bar: 5 cm (shorter bar for Fig.
(1) Brasilia decipiens (Buckman) [M], SMNS 70519/34. (2) Graphoceras cavatum (Buckman) [M], SMNS 70519/35. (3) G. cf. v-scriptum Buckman [M], SMNS 70519/36. (4a, b) B. aff. decipiens (Buckman) [M], SMNS 70519/37. (5) G. fallax (Buckman) [M], SMNS (70519/38. (1–5) Hechingen-Beuren (Heiligenbach), Achdorf Formation, Upper Aalenian, Concavum Zone (Concavum Subzone), cavatum biohorizon. Asterisk marks beginning of the bodychamber. Scale bar: 5 cm.
(1a, b) Brasilia bradfordensis (Buckman) [M], Bed 2, Bradfordensis Zone, (Bradfordensis Subzone), SMNS 70519/39. (2) Ludwigella cornu (Buckman) [m], SMNS 70519/40. (3) L. attracta (Buckman) [m], SMNS 70519/41. (4) L. micra (Buckman) [m], SMNS 70519/42. (5a, b) B. cf. decipiens (Buckman) [M], SMNS 70519/43. (1a–5b) Jungingen (Mühlbächle), Achdorf Formation, Bed 14 [Calceolabank], Upper Aalenian. (2–5b) Concavum Zone (Concavum Subzone), cavatum biohorizon. Asterisk marks beginning of the bodychamber. Scale bar: 5 cm.
(1a, b) Graphoceras aff. magnum (Buckman) [M], SMNS 70519/44. (2a, b) G. cf. cavatum (Buckman) [M], SMNS 70519/45. (3a, b) B. aff. decipiens (Buckman) [M], SMNS 70519/46. (1a–3b) Jungingen (Mühlbächle), Achdorf Formation, Bed 14 [Calceolabank], Upper Aalenian, Concavum Zone (Concavum Subzone), cavatum biohorizon. Asterisk marks beginning of the bodychamber. Scale bar: 5 cm.
(1a, b) Graphoceras cf. cavatum (Buckman) [M], SMNS 70519/47. (2a, b) G. cavatum (Buckman) [M], SMNS 70519/48. (1a–2b) Jungingen (Mühlbächle), Achdorf Formation, Bed 14 [Calceolabank], Upper Aalenian, Concavum Zone (Concavum Subzone), cavatum biohorizon. Asterisk marks beginning of the bodychamber. Scale bar: 5 cm.
(1a, b) Graphoceras decorum Buckman [M], SMNS 70519/49. (2a, b, 5a, b) G. formosum (Buckman) [M], (2) SMNS 70519/56, (5) SMNS 70519/50. (3a, b) Graphoceras pulcrum (Buckman) [M], SMNS 70519/51. (4) G. fallax (Buckman) [M], SMNS 70519/52. (1a–5b) Jungingen (Mühlbächle), Achdorf Formation, Bed 14 [Calceolabank], Upper Aalenian, Concavum Zone (Concavum Subzone), cavatum biohorizon. Asterisk marks beginning of the bodychamber. Scale bar: 5 cm.
(1a, b) Euaptetoceras cf. kochi (Prinz) [M], collection S. Pfister. Jungingen (excavation pit in the street “Im Binder”, about 0.5 km NW of the Mühlbächle stream), Achdorf Formation, Bed 14 [Calceolabank], Upper Aalenian, Concavum Zone (Concavum Subzone), cavatum biohorizon. Asterisk marks beginning of the bodychamber. Scale bar: 10 cm.
(1, 2) Gryphaea calceola Quenstedt, Jungingen, Mühlbächle, Calceolabank, SMNS 70528/1–2. (3, 4) juveniles of Gryphaea calceola Quenstedt, Jungingen, Mühlbächle, marlstone above Calceolabank, SMNS 70528/3–4. (5) Inoperna sowerbyana (dʼOrbigny), Jungingen, Starzel river, Inopernabank, SMNS 70528/5. (6) Pinna sp., Jungingen, Starzel river, Inopernabank, SMNS 70528/6. (7) Trigonia alemanica Rollier, Balingen-Zillhausen, Roschbach, Calceolabank, SMNS 70528/7. (8) Pholadomya lirata (Sowerby), Jungingen, Starzel river, Inopernabank, SMNS 70528/8. (9) Pholadomya fidicula (Sowerby), Hechingen-Beuren, Heiligenbach, Inopernabank, SMNS 70528/9. (10) Goniomya literata (Sowerby), Hechingen-Beuren, Heiligenbach, Inopernabank, SMNS 70528/10. (11) Mytiloceramus polyplocus (Roemer), Jungingen, Mühlbächle, Rostrote Kalkbank, SMNS 70528/11. (12) Oxytoma inaequivalvis (Sowerby), Jungingen, Starzel river, Inopernabank, SMNS 70528/12. (13) Pleuromya cf. uniformis (Sowerby), Jungingen, Starzel river, Inopernabank, SMNS 70528/13. (14) Belemnite rostrum, Hechingen-Beuren, Heiligenbach, Calceolabank SMNS 70529. (15) Asteracanthus personati (Quenstedt), Zillhausen Member, Starzel river in Schlatt, SMNS 97005. Scale for 1, 2: 50 mm; for 3-14: 20 mm, for 15a, b: 20 mm.
Number of species, genera and families in relation to zones and subzones. Indeterminable individuals were not considered. The maxima of the species within the zones are in bold. Indiv. = individuals.
Zone /Subzone | Heiligenbach | |||||||
---|---|---|---|---|---|---|---|---|
no. of indiv. | indiv. / sample | species / new | genera / new | families / new | ||||
Discites-Ovale | 374 | 125 | 15 | 4 | 9 | 1 | 7 | 1 |
Concavum | 2572 | 161 | 58 | 34 | 29 | 10 | 13 | 3 |
Gigantea | 169 | 42 | 35 | 18 | 20 | 6 | 9 | 1 |
Bradfordensis | 25 | 25 | 12 | 5 | 7 | 1 | 5 | |
Murchisonae | 126 | 63 | 17 | 9 | 11 | 2 | 7 | |
Comptum | 65 | 33 | 8 | 1 | 6 | 2 | 4 | 1 |
Opalinum | 360 | 28 | 34 | 15 | 9 | |||
Total | 3691 | 109 | 38 | 15 |
As
In the present study and in the Geisingen section, a total of 33 genera and species were identified which are also known from the English, Scottish and Irish Aalenian and Lower Bajocian. Cytherella apostolescui, Cytherelloidea catenulata, Cyth. lordi, Cytheropterina cribra, Eocytheridea elongata, Eoc. lacunosa, Eucytherura liassica, Euc. michelseni, Euc. transversiplicata, Kinkelinella (Ekt.) triangula, Macrocypris aequabilis, M. liassica, Procytherura celtica, Proc. euglyphea, Proc. multicostata, and many others indicate a marine connection between these two sedimentary basins across the Paris Basin.
6.1.1 Opalinum Zone
Of the 34 species detected in the Heiligenbach section in the upper part of the Opalinuston Formation, 21 species are restricted to the Opalinum Zone or occur here for the last time. In accordance with the Geisingen clay pit (
The ostracod assemblage of the upper Opalinuston Formation, Zillhausen Subformation (
6.1.2 Opalinum Zone (“Comptum” Subzone) to Murchisonae Zone
The stratigraphically insignificant ostracod faunal assemblage of the “Comptum” Subzone and Murchisonae Zone has little in common with previously studied sections of the Swabian Alb. According to
6.1.3 Bradfordensis Zone
The ostracod assemblage of this part of the section shows good accordance with that of the Geisingen section with 15 common species. In contrast, the similarities with
Progonocythere scutula, first described from the Geisingen Oolite (Gigantea Subzone;
The samples following higher up yielded Balowella catena, an index species of the Ohmerti-catena assemblage (
6.1.4 Concavum Zone
Apart from the zonal index species Camptocythere pusilla, Plumhofficythere clavatoides (Cytheridae, n. gen. sp. nov. 1 Plumhoff) is restricted to the Concavum Zone in northern Germany (
Herein we focus on the ammonites from the Inopernabank up to the Rostrote Kalkbank.
SW Germany: From the few data available it is most likely that the ammonites from the Inopernabank and the Rostrote Kalkbank are slightly younger compared to the ammonites from the decipiformis biohorizon of Geisingen (westernmost Swabian Alb). The few Graphoceras specimens from the Inopernabank are slightly more depressed and more involute compared to the “Graphoceras-morphology” of B. decipiformis (in a chronospecific sense as described in
The cavatum biohorizon (index species: Graphoceras cavatum; Calceolabank and Rostrote Kalkbank) is younger compared to the decipiformis biohorizon of Geisingen (
Ammonites of the Formosum Subzone occur in the “Bunte Mergel” and “Tonhorizont E1” of Ringsheim (Upper Rhine Valley) and in the Konglomeratbank/basal part of the Sowerbyi-Oolith near Achdorf (Wutach area). However, these beds are not yet subdivided into biohorizons.
SW England: The decipiens biohorizon (Bradfordensis Zone, Gigantea Subzone) is slightly older than the cavatum biohorizon of SW Germany, because therein occur Graphoceras and large-sized Brasilia (up to 0.4 m in diameter) in roughly equal numbers (
Besides the ammonites described and discussed above, the macrofauna of the Achdorf Formation is mainly composed of bivalves. Only two species, Gryphaea calceola (Quenstedt, 1843) and Inoperna sowerbyana (dʼOrbigny, 1850) are more abundant, especially the former, which occurs in masses, but only in a few beds. Gryphaea calceola (Fig.
Byssate bivalves are represented by isolated valves of Mytiloceramus polyplocus (Roemer, 1857), Oxytoma inaequivalvis (Sowerby, 1819) and the pectinids Propeamussium pumilum (Lamarck, 1819), Chlamys textoria (Schlotheim, 1820) and Entolium corneolum (Young & Bird, 1828). Mytiloceramus polyplocus (Fig.
Crinoid remains were noticed in the field in some beds of the Zillhausen Member and in polished sections of the Onkoidbank bed. Among arthropods, in the Upper Aalenian claystones of the Zollernalb occasionally tanaidacean remains occur. Specimens preserved in claystones had been originally misidentified and described as tiny salamanders by F. v. Huene (see
Finally, a single tooth of Asteracanthus personati (Quenstedt, 1857) Fig.
The consideration of small species results in a much higher diversity of the ostracod fauna of the Upper Aalenian in SW Germany than previously known. The Heiligenbach section and the Geisingen clay pit (
The uppermost Lower Aalenian is well characterized by the presence of Aphelocythere pygmaea, Acrocythere pumila and Metacytheropteron opalinum. Eucytherura foveolata and Cardobairdia tesakovae have also only been found in this part of the section so far. Cytherella apostolescui appears for the first time at the base of the Achdorf Formation. Higher up in the Achdorf Formation, especially from the Gigantea subzone on, several stratigraphically important species appear like Balowella catena, Cytherelloidea lordi, Cytheropterina alacostata, Eucytherura eberti, Kinkelinella levata, Pleurocythere ohmerti, Procytherura multicostata, and Progonocythere scutula.
Among the ostracod assemblages, cytherurids show the most striking development with the first appearance of five species in the Gigantea Subzone and 14 species in the Concavum Zone. During the same period the total number of genera increases from 7 (from 5 families) in the Bradfordensis Zone to 20 (9 families) in the Gigantea Subzone and 29 (13 families) in the Concavum Zone.
The variation within ammonites of the family Graphoceratidae in southwestern Germany reflects the evolution of Graphoceratidae from the geisingensis biohorizon via the decipiformis biohorizon (uppermost Bradfordensis Zone; see
We thank C. Tetzel (Freiburg i. Br.) for her assistance in describing and sampling the sections studied. N. Ainsworth (St. Albans), A. Lord (London/Frankfurt a. M.) and E. Tesakova (Moscow) gave numerous valuable hints, which is gratefully acknowledged. Special thanks go to S Herbstritt, A. Schill, S Wendt (all Freiburg i. Br.) for their help in processing the samples. C. Gasco-Martín (Stuttgart) is thanked for taking the SEM photographs, G Fischer (Freiburg i. Br.) for preparing the illustrations and ostracod plates in customary high quality. S Pfister (Ringingen) provided a stratigraphically important ammonite. M. Pfister (Ringingen) and H. Unmuth (Ringingen) are thanked for valuable information. R. B Chandler (London) supported us in the determination of some of the ammonites. G Stappenbeck (Sulz am Neckar) assisted in the field work. A. Hofbauer (Wendlingen) prepared the figured Trigonia. Special thanks go to A. Lord (London/Frankfurt a. M.) and B Hostettler (Glovelier) for their valuable reviews.
After submission of the original draft of this manuscript, the "Comptum" Subzone of the Opalinum Zone has been renamed Bifidatum Subzone, and the number of distinguished biohorizons in the Opalinum Zone (Opalinum and Bifidatum subzones) (Fig.